Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Some vehicles are configured to operate in an autonomous mode in which the vehicle navigates through an environment with little or no input from a driver. Such a vehicle typically includes a mapped knowledge of a graph of roads which is a subset of all known roads, and one or more sensors that are configured to sense information about the environment. The vehicle is thus able to drive on the graph of roads in the autonomous mode.